以下实例演示了如何获取指定 URL 的响应头信息：
import java.io.IOException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Map;
import java.util.Set;
public class Main {
public static void main(String[] args) throws IOException{
URL url = new URL("http://www.dida100.com");
URLConnection conn = url.openConnection();
Map headers = conn.getHeaderFields();
Set<String> keys = headers.keySet();
for( String key : keys ){
String val = conn.getHeaderField(key);
System.out.println(key+" "+val);
}
System.out.println( conn.getLastModified() );
}
}以上代码运行输出结果为：
Transfer-Encoding chunked null HTTP/1.1 200 OK Server Tengine/1.3.0 Connection keep-alive Vary Cookie Date Mon, 04 May 2015 03:54:05 GMT X-Pingback http://www.dida100.com/xmlrpc.php X-Powered-By PHP/5.3.15 Content-Type text/html; charset=UTF-8